+ if (var->name != NULL && strcmp(var->name, "gl_FragCoord") == 0) {
+
+ /* Section 4.3.8.1, page 39 of GLSL 1.50 spec says:
+ *
+ * "Within any shader, the first redeclarations of gl_FragCoord
+ * must appear before any use of gl_FragCoord."
+ *
+ * Generate a compiler error if above condition is not met by the
+ * fragment shader.
+ */
+ ir_variable *earlier = state->symbols->get_variable("gl_FragCoord");
+ if (earlier != NULL &&
+ earlier->data.used &&
+ !state->fs_redeclares_gl_fragcoord) {
+ _mesa_glsl_error(loc, state,
+ "gl_FragCoord used before its first redeclaration "
+ "in fragment shader");
+ }
+
+ /* Make sure all gl_FragCoord redeclarations specify the same layout
+ * qualifiers.
+ */
+ if (is_conflicting_fragcoord_redeclaration(state, qual)) {
+ const char *const qual_string =
+ get_layout_qualifier_string(qual->flags.q.origin_upper_left,
+ qual->flags.q.pixel_center_integer);
+
+ const char *const state_string =
+ get_layout_qualifier_string(state->fs_origin_upper_left,
+ state->fs_pixel_center_integer);
+
+ _mesa_glsl_error(loc, state,
+ "gl_FragCoord redeclared with different layout "
+ "qualifiers (%s) and (%s) ",
+ state_string,
+ qual_string);
+ }
+ state->fs_origin_upper_left = qual->flags.q.origin_upper_left;
+ state->fs_pixel_center_integer = qual->flags.q.pixel_center_integer;
+ state->fs_redeclares_gl_fragcoord_with_no_layout_qualifiers =
+ !qual->flags.q.origin_upper_left && !qual->flags.q.pixel_center_integer;
+ state->fs_redeclares_gl_fragcoord =
+ state->fs_origin_upper_left ||
+ state->fs_pixel_center_integer ||
+ state->fs_redeclares_gl_fragcoord_with_no_layout_qualifiers;
+ }
+